Bump Newtonsoft.Json in /Source/EasyNetQ.ExternalScheduler

Bumps [Newtonsoft.Json](https://github.com/JamesNK/Newtonsoft.Json) from 12.0.3 to 13.0.2.
- [Release notes](https://github.com/JamesNK/Newtonsoft.Json/releases)
- [Commits](JamesNK/Newtonsoft.Json@12.0.3...13.0.2)

---
updated-dependencies:
- dependency-name: Newtonsoft.Json
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

Source/EasyNetQ.ExternalScheduler/EasyNetQ.ExternalScheduler.csproj

@@ -19,7 +19,7 @@
   <ItemGroup>
     <PackageReference Include="EasyNetQ" Version="[5.5.0,6.0.0)" />
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All" />
-    <PackageReference Include="Newtonsoft.Json" Version="12.0.3" />
+    <PackageReference Include="Newtonsoft.Json" Version="13.0.1" />
     <PackageReference Include="RabbitMQ.Client" Version="[6.2.1,6.3.0)" />
     <PackageReference Include="LibLog" Version="5.0.8">
       <PrivateAssets>all</PrivateAssets>